The semiconductor integrated circuit (IC) industry has experienced rapid growth. Technological advances in IC materials and design have produced generations of ICs where each generation has smaller and more complex circuits than the previous generation. However, these advances have increased the complexity of processing and manufacturing ICs and, for these advances to be realized, similar developments in IC processing and manufacturing are needed. In the course of integrated circuit evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometry size (i.e., the smallest component (or line) that can be created using a fabrication process) has decreased.
To achieve greater functional density and miniature geometry sizes for semiconductor devices, various advanced lithography techniques have been proposed and implemented. Among these advanced lithography techniques is maskless lithography, which does not require a photomask to perform a lithography process. For example, in an electron beam lithography process, beams of electrons are emitted in a patterned fashion on a resist material to expose and develop the resist material into a patterned resist mask. The patterned resist mask can then be used to pattern the various layers of a substrate below.
Maskless lithography offers advantages such as enhanced lithography resolution and patterning precision. However, existing maskless lithography processes also have drawbacks such as long processing time and low throughput. Therefore, while existing maskless lithography processes have been generally adequate for their intended purposes, they have not been entirely satisfactory in every aspect.